<HTML><HEAD><TITLE>lookup(+Tree, ++Key, ?Value)</TITLE>
</HEAD><BODY>[ <A HREF="index.html">library(m_tree234)</A> | <A HREF="../../index.html">Reference Manual</A> | <A HREF="../../fullindex.html">Alphabetic Index</A> ]
<H1>lookup(+Tree, ++Key, ?Value)</H1>
Search a tree for a key.
<DL>
<DT><EM>Tree</EM></DT>
<DD>A 2-3-4 tree
</DD>
<DT><EM>Key</EM></DT>
<DD>A key to search for
</DD>
<DT><EM>Value</EM></DT>
<DD>The value corresponding to Key
</DD>
</DL>
<H2>Description</H2>
	<P>
	This predicate searches the tree Tree for an entry with key Key.
	If the key is found, then it attempts to unify the corresponding
	value with Value.  If the key is not found, then it aborts with
	a runtime error.
	</P>
	<P>
	This predicate should only be called with trees created by other
	predicates from the tree234 module.
	</P>
	
<H3>Fail Conditions</H3>
Fails if Value does not unify with the value corresponding to Key.
<H3>Resatisfiable</H3>
no
<H2>See Also</H2>
<A HREF="../../lib_public/m_tree234/member-3.html">member / 3</A>, <A HREF="../../lib_public/m_tree234/search-3.html">search / 3</A>
</BODY></HTML>
